The return to normality could only last for weeks amid the surge in Delta variant cases, Government scientists warned as Boris Johnson told Britons not to get 'demob happy' amid a relaxation of restrictions.
The Prime Minister signalled a 'big bang' end to lockdown on July 19, saying it was now or never for a return to normality, as he acknowledged the pandemic was 'far from over' and that daily Covid cases could top 50,000 by 'Freedom Day' in a fortnight.
He claimed further delay would run the risk of trying to reopen in autumn or winter when 'the virus has an edge'.
And in a downbeat assessment, the Scientific Advisory Group for Emergencies (Sage) said that even if hospitalisations and deaths remained low, there were major risks in letting cases surge.
The group warned that should a 'variant of concern' arrive that threatened immunity, lockdown restrictions would need to reimposed for much longer.
In newly-released documents which advised on controlling the virus long-term, Sage warned that some 'baseline measures' may have to stay, with 'sustained behavioural change' necessary.
And at a sombre Downing Street press conference, Mr Johnson warned against going 'demob happy' at the ending of most coronavirus restrictions on July 19.
And he toned down previous pledges that the path out of lockdown would be 'irreversible' – with restrictions potentially returning. A final decision on whether to press ahead on July 19 will be taken at the start of next week but seems almost certain to be approved.
Mr Johnson said the vaccine programme was continuing to be a success and retaining restrictions would 'inevitably take their toll on people's lives and livelihoods – on people's health and mental health'.
Dropping the curbs will mean the end of all legal limits on socialising, which have wrecked family gatherings for 16 months, and the scrapping of social distancing rules that have hobbled pubs, restaurants and the arts.
In other developments:
The gap between vaccine doses was cut from 12 weeks to eight for the under-40s to give more people the protection of a second jab; Britain recorded another 27,334 cases of the virus, but only nine more Covid-related deaths; London Mayor Sadiq Khan said he would work with transport providers to keep mask rules in place; An official review of social distancing warned keeping the 'economically disruptive' one metre-plus rule in place would constrain the recovery; Health Secretary Sajid Javid said the requirement to isolate entire school classes and years would end on July 19; Mr Johnson said the cap on the number who can visit loved ones in care homes would be scrapped; The PM said he hoped to lift quarantine restrictions on fully vaccinated holidaymakers returning from amber list countries – but did not say when; Downing Street said social distancing would remain in airports, amid concerns about the virus spreading in arrival halls; Luxembourg PM Xavier Bettel, 48, was admitted to hospital in a 'serious but stable' condition with Covid, despite having been vaccinated
Chief Scientific Adviser Patrick Vallance, Prime Minister Boris Johnson and Chief Medical Officer for England Chris Whitty
Sir Patrick Vallance Government Chief Scientific Adviser and Chief Medical Officer (CMO) for England, Chris Whitty, attend Downing Street Covid press conference
Experts said self-isolation when ill would remain 'critical' and working from home was a 'highly effective' long-term option. And in a grim sign that Britons face a return of some curbs in the near future, Sage added: 'Stronger measures may be desirable for autumn and winter.'
Mr Johnson's decision to defy gloomy warnings from scientists and Labour leader Sir Keir Starmer was warmly cheered by business chiefs and Conservative MPs.
However there was confusion over quarantine for summer holidays, the end of mandatory mask wearing and the future of working from home.
Mr Johnson's leading scientific advisers appeared cautious at the press conference, with chief medical officer Chris Whitty saying the third Covid wave was 'significant and rising'.
Sage scientific advisers published documents saying there was a 'significant risk' in allowing cases to rise – and that restrictions might need to return this winter. And in a sign that the political consensus over Covid was fracturing, Sir Keir branded Mr Johnson's announcement 'reckless'.
At last night's briefing, Mr Johnson warned cases were predicted to rise to 50,000 a day later this month and that 'we must reconcile ourselves, sadly, to more deaths from Covid'.
But he declared: 'We must be honest with ourselves that if we can't reopen our society in the next few weeks, when we will be helped by the arrival of summer and by the school holidays, then we must ask ourselves: when will we be able to return to normal?'
He said a further delay would 'run the risk of either opening up at a very difficult time when the virus has an edge' in the autumn or winter or 'putting everything off to next year'.
Chief scientist Sir Patrick Vallance said Covid cases were doubling every nine days and hospitalisations were also rising, albeit at a slower rate. 'The vaccines have weakened the link, not broken it,' he said. Both he and Professor Whitty said they would continue to wear face masks in busy settings. Professor Whitty acknowledged there were 'some advantages' to reopening in the summer and Downing Street denied a claim from Dominic Cummings that the Prime Minister had overruled his scientific advisers.
In a bold shift despite daily Covid cases rising a fifth in a week to 27,000, Boris Johnson told a Downing Street briefing that the government will no longer issue 'top down' orders after July 19 and people must use their common sense to manage the risks
Boris Johnson pushed the button on a 'big bang' Freedom Day unlocking tonight with social distancing rules, mask laws and the work from home order set to go
A Whitehall source said last night: 'The majority view among the scientists is in favour. Yes there are some noises off in the media, but they are in a minority position.'
As Mr Javid set out the unlocking measures in the Commons some Conservative MPs shouted 'hallelujah'.
Former chief whip Mark Harper said it was 'great to see Cabinet ministers now publicly saying what my Covid Recovery Group colleagues and I have been saying for ages – there will never be zero risk from Covid'.
The senior Tory MP added: 'Let's not squander our world-class rollout of effective vaccines.'
Shevaun Haviland, director general of the British Chambers of Commerce, said that although more detail was needed, the announcement was 'a much-needed step on the road to normality and we welcome the Prime Minister setting out the direction of travel in advance of reopening'.
Kate Nicholls, chief executive of UKHospitality, which represents the leisure and hospitality sector, said: 'The Prime Minister's announcement marks a major milestone in how England will come to live with Covid and will be celebrated by hospitality business owners and their staff across the country.'
But Sir Keir suggested elements of the lockdown should continue, saying: 'To throw off all protections at the same time, when the infection rate
